Many people (including many non-LDS religious scholars) classify Mormons as “non-creedal Christians” specifically because we allow a degree of doctrinal flexibility and fluidity that simply baffles those who are tied tightly to their own creeds - those who want to know the full and complete word of God by what has been said in the past.
We, on the other hand, have no doctrinal problem with competing beliefs among apostles and prophets concerning things that have not been revealed in canonized scripture - and even among some things that we consider to be non-revealed parts of that canon. Therefore, for every “Brigham Young said . . .” there is a “Parley P Pratt said . . .” - and for every “Bruce R McConkie said . . .” there is a “Gordon B Hinckley said . . .” That’s fine, since we believe many of the details have not been revealed yet, even though the proper framework has been restored. In the face of competing speculations, the general rule is follow the one being said in our own time - as that represents the understanding of our own time.The contrast between such an incredibly liberal theology and such a clearly conservative hierarchy - and between a widely divergent local lay ministry and a highly correlated central authority - just confounds most people. I happen to love it, since it embodies "I teach them correct principles and let them govern themselves" so well.